Collapsible octahedral corner reflector



Oct. 6, 1964 FIG.4.

P. A. LOWERY ETAL 3,152,329

COLLAPSIBLE OCTAHEIDRAL CORNER REFLECTOR Filed Sept. 11, 1961 02L 2INVENTORSI "M 2 BYM, M I M 9'- ATTORN5 United States Patent "ice3,152,329 CGLLAPSIBLE OCTAHEDRAL CORNER REFLECTOR Peter Albert Lowery,Retford, Harold Edmund Grilfiths Richards, Mudeford, near Christchurch,and Bernard Thomas Triggs Pools, London, England, assignors to ChemriugLimited, Thornton Heath, England, a British company Filed Sept. 11,1961, Ser. No. 137,149 3 Claims. (Cl. 34318) This invention relates toradar reflectors of the corner type.

A known collapsible corner reflector comprises four triangular panelsand a single square panel all of flexible reflecting material. Acollapsible supporting framework is provided for supporting thetriangular panels in perpendicular planes and for supporting the squarepanel in a plane at right angles to the planes in which the triangularpanels are disposed. The framework includes a central post, a memberslidable on the post, four supporting members each pivoted at one end tothe slidable member, and means for selectively securing the slidablemember against sliding movement on the post at a position adjacent thesquare panel. The collapsing of the framework is effected by moving theslidable member towards those apices of the triangular panels which areremote from the square panel.

According to the present invention we provide an octaredral reflector ofthe type referred to comprising a single square panel flexiblereflecting material as a base, four triangular panels of reflectingmaterial disposed at 90 to one another above the base to form fourcorners of the reflector and four triangular panels of reflectingmaterial disposed at 90 to one another below the base to form the otherfour corners of the reflector, four arms for supporting the retainingpanels in their operative positions and a central post to which the armsare pivotally connected at one end, the arrangement being such that thevarious parts of the reflector may be folded substantially intoparallelism with the central post when the reflector is stored.

Also according to the invention, we provide an octahedral reflector ofthe type referred to which may be folded up and opened out as desired,the reflective material being secured to the top of a central post, tofour arms pivotally mounted at or near the center or midpoint of saidpost on a collar on the post and to a second collar slidable on the postbelow the center from a closed position adjacent to the center to anopen position near the bottom, tensioning wire being provided to holdthe unsupported sides of the reflective material in position.

The base and the panels are preferably made of metalcoated plastic meshe.g. silvered nylon and the post and arms may be made of metal e.g.light metal such as aluminium or stronger metal such as stainless steel.

One embodiment of the invention will now be described in more detail byway of example with reference to the accompanying drawings in which:

FIGURE 1 is a perspective view of the reflector.

FIGURE 2 is a detail view of the means of connecting the arms to thepost,

FIGURE 3 is a detail view of the bottom of the post, and

FIGURE 4 is a sectional view of the collapsible reflector disclosing amodified form of the slidable collar.

In this embodiment the central post 1 consists of a single metal tubewhich extends from end to end of the reflector. At a position near thecenter of the post 1 a collar 2 is fixed. Four arms 3 are pivotallyconnected to the fixed collar in such a Way that they can be folded upagainst the post or can be extended outwards at 90 3,152,329 PatentedOct. 6, 1964 thereto. Reflective mesh material 4 is hemmed and shapedand is secured into position to provide the base 4, the four panels 5above the base, and the four panels 6 below the base. To do this themesh material may be provided with a sleeve 9 at the center throughwhich the post 1 is extended. Each arm is also extended down a sleeve 10provided for this purpose. In addition hems 11 are provided to extendfrom the outer end of each arm to the top of the post, i.e., along thefree side of each triangular panel 5 and a wire 12 is passed along thehems and through slots 13 or the like at the end of each arm and at thetop of the post, the purpose of the wire being to assist in tensioningthe reflector when it is opened out.

The four corners below the base are formed in much the same way as thefour corners above the base but instead of being fixed to the bottom ofthe post, triangular panels 6 of mesh material are secured to a slidablecollar 7 on the central post 1. When the reflector is collapsed theslidable collar 7 lies close to the fixed collar 2, but when thereflector is opened out as in FIGURE 1 the slidable collar 7 is at thelower end of the central post :1 so that the triangular panels 6 formingthe corners below the base 4 are in their operative position. Areleasable catch 8 is provided at the lower end of the post 1 to holdthe slidable collar 7 in the open position. Suitable strengthening meansmay be provided for the reflective material where required. For example,extra material 14- may be provided where the material is attached to thetop of the post 1, and to the end of each arm 3. If desired the centralpost 1 may be made in two parts so that it can be dismantled forpacking. Two or more of these octahedral reflectors may be used togetherto form a cluster.

To open out the reflector, the arms 3 are pivoted on the fixed collar 2until they are at to the post 1 and the slidable collar 7 is moved downthe post 1 until it is engaged with the catch 8. In this position oneside of each triangular panel 5 and 6 is supported by the central post1, one side by an arm 3, and one side by a wire 11 so that eachtriangular panel has a rigid support on two sides. The arms 3 formdiagonal supports for the base and the sides of the base are held inposition on the arms by wire. In this way a very elfective octahedralcorner reflector is provided. To fold up the reflector the catch 8 isreleased, e.g., by manual pressing, the slidable collar 7 is moved upthe central post 1 and the arms 3 are folded up so that the outer end ofeach arm 3 lies adjacent to the top of the central post 1. Naturally thetensioning wire 11 may be a continuous length which is extended alongone hem round the end of an arm, along another hem, and so on; for thispurpose the ends of the arms and the top of the central post may beslotted as at 13.

We have therefore provided an octahedral corner reflector of the typereferred to which maybe folded up and opened out as desired. Thereflective material is secured to the top of a central post, to fourarms pivotal. y mounted at the center on a collar on the post, and to asecond collar slidable on the post below the center from a closedposition adjacent to the center to an open position near to the bottom.Tensioning wires are provided to hold the unsupported side of thereflective material in position.

Instead of being fixed, e.g., by a rivet at a position near to thecenter of the post the collar 2 may be held in position by a spring clip15 and if desired a clip 16 may be used giving two or more positions forthe collar so that it may be adjusted in the same manner as the snapcatch 8 which may also have two or more positions 8a, 8b and 80.

In another construction spring means 17 may be provided to make thereflector self-erecting. To achieve this result the center post 1 may beextended beyond the catch 8 for a distance to enable springs 18 tooperate over a suflicient length to erect the reflector. These springsmay extend between the slidable collar to a fixed point 19 on theextended center post so that they draw the slidable collar on to itsspring catch. In this construction the reflector may erect automaticallyas soon as it is freed from restraint.

What We claim is:

1. A collapsible octahedral corner reflector comprising: a centralsupporting post; a first collar on said post movable to at least twopositions near the midpoint of said post; a plurality of spring clipsdefining said positions; four supporting arms at right angles to eachother each pivotably attached to one end to said first collar; a secondcollar slidably mounted on said post from a closed position adjacent andbelow said first collar to an open position near the bottom of saidpost; radar-reflective flexible material shaped to provide a square basepanel having its corners secured to the outer ends of said arms, havingits center secured to said first collar and having its diagonal portionssecured to said arms along their length; four right-angled triangularupper panels of radar-reflective flexible material symmetricallydisposed above said base panel between said post and said arms, each ofsaid upper panels having its right-angled corner secured to said firstcollar, having its second corner secured to the end of the armsupporting it and having its third corner secured to the top of saidpost; four right-angled triangular lower panels of radar-reflectiveflexible material symmetrically disposed below said base panel betweensaid post and said arms, each of said lower panels having itsright-angled corner secured to said first collar, having its secondcorner secured to the end of the arm supporting it and having its thirdcorner attached to said second collar; each of said triangular panelshaving a hem in its hypotenuse side and a tensioning wire passingthrough the hem, the tensioning wire in said upper panels extending fromsaid post to said arms and the tensioning wire in said lower panelsextending from said arms to said second collar; and means for adjustablysecuring said second collar on said post in the open position wherebysaid arms are spread in a plane at right angles to said post.

2. A corner reflector according to claim 1 further comprising springmeans attached to said second collar and to a fixed point on said centerpost, said spring means being effective to move said second collar alongthe post to bring the pivoted arm's into a plane at right angles to thepost.

3. A corner reflector according to claim 1 wherein said radar-reflectivematerial is metal-coated plastic mesh.

References Cited in the file of this patent UNITED STATES PATENTS2,450,417 Bossi Oct. 5, 1948 2,534,710 Golian et a1 Dec. 19, 19502,604,644 Tilton July 29, 1952 2,639,426 McAuley et a1. May 19, 1953FOREIGN PATENTS 746,300 Great Britain Mar. 14, 1956 812,376 GreatBritain Apr. 22, 1959

1. A COLLAPSIBLE OCTAHEDRAL CORNER REFLECTOR COMPRISING: A CENTRALSUPPORTING POST; A FIRST COLLAR ON SAID POST MOVABLE TO AT LEAST TWOPOSITIONS NEAR THE MIDPOINT OF SAID POST; A PLURALITY OF SPRING CLIPSDEFINING SAID POSITIONS; FOUR SUPPORTING ARMS AT RIGHT ANGLES TO EACHOTHER EACH PIVOTABLY ATTACHED TO ONE END TO SAID FIRST COLLAR; A SECONDCOLLAR SLIDABLY MOUNTED ON SAID POST FROM A CLOSED POSITION ADJACENT ANDBELOW SAID FIRST COLLAR TO AN OPEN POSITION NEAR THE BOTTOM OF SAIDPOST; RADAR-REFLECTIVE FLEXIBLE MATERIAL SHAPED TO PROVIDE A SQUARE BASEPANEL HAVING ITS CORNERS SECURED TO THE OUTER ENDS OF SAID ARMS, HAVINGITS CENTER SECURED TO SAID FIRST COLLAR AND HAVING ITS DIAGONAL PORTIONSSECURED TO SAID ARMS ALONG THEIR LENGTH; FOUR RIGHT-ANGLED TRIANGULARUPPER PANELS OF RADAR-REFLECTIVE FLEXIBLE MATERIAL SYMMETRICALLYDISPOSED ABOVE SAID BASE PANEL BETWEEN SAID POST AND SAID ARMS, EACH OFSAID UPPER PANELS HAVING ITS RIGHT-ANGLED CORNER SECURED TO SAID FIRSTCOLLAR, HAVING ITS SECOND CORNER SECURED TO THE END OF THE ARMSUPPORTING IT AND HAVING ITS THIRD CORNER SECURED TO THE TOP OF SAIDPOST; FOUR RIGHT-ANGLED TRIANGULAR LOWER PANELS OF RADAR-REFLECTIVEFLEXIBLE MATERIAL SYMMETRICALLY DISPOSED BELOW SAID BASE PANEL BETWEENSAID POST AND SAID ARMS, EACH OF SAID LOWER PANELS HAVING ITSRIGHT-ANGLED CORNER SECURED TO SAID FIRST COLLAR, HAVING ITS SECONDCORNER SECURED TO THE END OF THE ARM SUPPORTING IT AND HAVING ITS THIRDCORNER ATTACHED TO SAID SECOND COLLAR; EACH OF SAID TRIANGULAR PANELSHAVING A HEM IN ITS HYPOTENUSE SIDE AND A TENSIONING WIRE PASSINGTHROUGH THE HEM, THE TENSIONING WIRE IN SAID UPPER PANELS EXTENDING FROMSAID POST TO SAID ARMS AND THE TENSIONING WIRE IN SAID LOWER PANELSEXTENDING FROM SAID ARMS TO SAID SECOND COLLARS; AND MEANS FORADJUSTABLY SECURING SAID SECOND COLLAR ON SAID POST IN THE OPEN POSITIONWHEREBY SAID ARMS ARE SPREAD IN A PLANE AT RIGHT ANGLES TO SAID POST.